Project Summary Metabolic reprogramming is recognized as a hallmark of cancer cells, and a deeper understanding of these metabolic changes can lead to the development of novel and promising therapeutics. Activation of de novo lipid synthesis and epigenetic reprogramming are both common features of many cancers. Acetyl-CoA is the metabolic building block for newly synthesized lipids in the cell. Deregulated lipid synthesis is a key problem in metabolic disorders, and has been shown to support tumor growth. Acetyl-CoA is also the donor substrate for all histone and non-histone protein acetylation. Previous studies in our lab show that histone acetylation is metabolically sensitive in cancer cell lines and tissues in vivo. How metabolic regulation of histone acetylation subsequently affects gene expression and signaling in tumorigenesis remains an area of active investigation. Another hallmark of cancer is the ability to evade immune detection or destruction through a wide variety of mechanisms. Studies identifying metabolic rewiring of immune cells during differentiation or activation have prompted research into how immunometabolism is disrupted within tumors to suppress anti- tumor immunity. However, the exact mechanisms of interplay between cancer and immune cell metabolism within a tumor remain largely unknown. The aims presented in the pre-doctoral phase of this proposal are designed to further understand the role of cellular metabolism in promoting tumorigenesis. In Aim 1, I investigate the role of ACLY in regulating processes such as de novo lipid synthesis and histone acetylation in cells using genetic and pharmacological perturbations of cellular metabolism coupled with mass-spectrometry based metabolomic techniques and other biochemical methods. In Aim 2, my previous findings will be translated in vivo to investigate how ACLY loss impacts hepatocellular carcinoma development in the context of non-alcoholic fatty liver disease, which has been identified as a risk factor for hepatocellular carcinoma in human patients. I will utilize a dietary stress and carcinogen-induced model of HCC in mice harboring a liver-specific knockout of Acly to study how processes such as de novo lipid synthesis and epigenome remodeling are impacted in this context. The ultimate goal of these aims is to define ACLY functions in cellular metabolism in the context of dietary stress and hepatocellular carcinoma for the application of ACLY inhibitors as a therapeutic strategy in the prevention and treatment of HCC. In Aim 3, I propose to build upon the technical and conceptual expertise in cellular and tumor metabolism acquired in my pre-doctoral training by pursuing a post-doctoral fellowship in tumor immunology and immunometabolism. I describe potential methods to investigate how metabolic reprogramming by cancer cells can impact immune cell function within a tumor. The goal of these studies is to identify how modulating cancer or immune cell metabolism can favor anti-tumor immune responses to develop novel therapeutic strategies.